Automotive start-stop systems designed to reduce fuel consumption and CO2 emissions work by automatically shutting the engine down when the vehicle is stationary. However, to try to balance fuel economy against other attributes such as climate comfort, start-stop systems typically include a number of ‘inhibitor’ signals that prevent the engine shutting down if it is needed for heating or cooling, or to reduced perceived ‘busyness’ of the system, etc.
Achieving an optimum balance between fuel economy and maintaining attributes such as consistent climate control that suits all customers in all situations is not possible since customer preferences vary wildly. Some customers prioritize fuel economy and would like the engine to shut down at every available opportunity, while others perceive start-stop as annoying and frequently disable it.
In current vehicles it is possible to disable the start-stop system and keep the engine running, using a disable switch, but there is no way to override the inhibitors to force the engine to shut down.
Vehicles, such as motor vehicles, may include a start-stop system configured to shut down an engine of the motor vehicle automatically when the engine is not required, e.g. when torque from the engine is not required to drive the vehicle, and to restart the engine automatically when desirable. For example, the engine may be shut down when the speed of the vehicle is below a threshold value, e.g. when the vehicle is stopped, and may be restarted automatically when a driver of the vehicle is preparing to move away after a stop or is attempting to accelerate the vehicle. Shutting down the engine in such circumstances reduces the idling time of the engine and improves the fuel efficiency and emissions of the motor vehicle.
When the engine of the motor vehicle is shut down by the start-stop system, the operation of one or more auxiliary systems of the motor vehicle, such as a climate control system of the vehicle, may be affected. It may therefore, be undesirable for the engine to be shut down automatically when such auxiliary systems are active. Furthermore, start-stop systems can sometimes be perceived as an annoyance by the driver, particularly if the start-stop system shuts down the engine too frequently or if the engine being shut down gives the impression that the vehicle cannot quickly move away from a stop.
Start-stop systems are often configured to balance the benefits to fuel consumption and emissions from shutting down the engine, with the annoyance that may be caused to the driver and the potential disruption to the operation of auxiliary systems of the vehicle.